The present invention relates generally to railway coupler connections, and more particularly to slack adjusted drawbar and coupler connections.
With the increased loads carried by today's trains, it is important to maintain close butted relationships between draft components to lessen impact forces under buff conditions and sudden pulling forces under draft conditions. Since most drawbar and coupler parts are cast with little or no finish machining to provide dimensional control, it is desirable to provide a coupling device which is self adjusting under various wear conditions to lessen the slack in such connections.
Known slack adjusters have comprised various sized shims which were inserted and replaced in couplers under various wear conditions. Self adjusting wedge shaped shims for articulated couplers, such as shown in U.S. Pat. No. 3,716,146, are also known.
It is also desirable to provide for the vertical and horizontal movement of such couplers as normally occurs when a train is negotiating a curve or a gradient. If equipped with a key drawbar assembly, the possible bending of the key or pin or even the bending or cracking of the drawbar or coupler shank must be considered due to the vertical motion of the drawbar or coupler shank. Such a situation is discussed in U.S. Pat. No. Re. 29,011, wherein a diverging coupler shank keyslot is shown to accommodate the vertical movements of the coupler shank.